I am going to buy a Macbook Air and will want to run Parallels (8, I suppose) on it. It comes with 4 GB RAM. I can upgrade to 8 GB RAM but it will take up to a month and I'd like it right away. I cannot upgrade after purchase. Is 4 enough? Or is it worth waiting to get the 8? Also, does it depend on the Windows version (32 or 640)?
Depends heavily on the usage (apps running) and obviously 64 bit consumes more RAM, but the short answer 4 GB is low for most cases except for light usage of virtualization.